What does tu you manque tellement?

"Tu you manque tellement" is grammatically incorrect. It should be "Tu me manques tellement".

Translation:

Tu me manques tellement - "I miss you so much."

Breakdown:

* Tu: You (informal, singular)

* me: me

* manques: miss (verb "manquer" in the present tense, second person singular)

* tellement: so much